1. Field of the Invention
The present invention relates generally to a seamless display apparatus having a plurality of panels, and more particularly, to a display apparatus having a plurality of panels, in which there is no invisible region between any two neighboring panels.
2. The Prior Arts
Electronic display boards are often used for public advertising purpose. Accordingly, large area LCD apparatuses are now highly demanded in the market. However, restricted by many factors, large area panels are usually manufactured with a high production cost and a low yield. As such, an alternative solution is proposed to obtain a large size panel by arranging a plurality of small size panels side by side.
Referring to FIG. 1, it illustrates a display structure of a conventional seamless display apparatus having a plurality of panels. The display structure includes a backlight module 7, a first LCD panel 51, a second LCD panel 53, a first concave lens 3, a second concave lens 5, and a protective glass 10. The protective glass 10 is positioned at a topmost side of the display structure, and the backlight module 7 is positioned at a bottommost side of the display structure. The first LCD panel 51 and the second LCD panel 53 are disposed over the backlight module 7. The first concave lens 3 is disposed positionally corresponding to and parallel with the first LCD panel 51, and the second concave lens 5 is positionally disposed corresponding to and parallel with the second LCD panel 53. With respect to the first LCD panel 51 and the second LCD panel 53, there is an invisible region 55. The first concave lens 3 is positioned over the backlight module 7 and under the protective glass 10. The protective glass 10 includes an image-presenting region S. The image-presenting region S is positioned corresponding to an invisible region 55.
The backlight module 7 provides an incident light. The incident light is transmitted through the first LCD panel 51 and reaches the first concave lens 3. According to the Snell's refraction law, the incident light provided to the first concave lens 3 is diverged thereby, and the light outputted from the first concave lens 3 then enters the image-presenting region S of the protective glass 10. Similarly, the incident light is transmitted through the second LCD panel 53 and reaches the second concave lens 5, and is diverged thereby, and the light outputted from the second concave lens 5 then enters the image-presenting region S of the protective glass 10.
Unfortunately, the concave lenses employed in the conventional display apparatus are very expansive and restricted for single size LCD panels. When larger LCD panels are used, the concave lens must be correspondingly larger. Further, the collimation accuracy between the concave lenses and corresponding LCD panels seriously affect the performance of the display apparatus. When strict criteria for assembly tolerance are applied, the production cost will be high, when less strict criteria are applied, the elimination of the invisible region may be adversely affected.
As such, a seamless display device which is cheaper, and has an eliminated invisible region is desired.